Gas separators commonly are used to facilitate pumping of fluids that may have a high gas to liquid ratio. The fluid is passed through a gas separator to separate the fluid into its liquid and gas components. The liquid component can then be directed into a pump designed for pumping liquid.
For example, in production of petroleum and other useful fluids from production wells, submergible pumping systems often are used to raise the fluids collected in a well. A typical submergible pumping system includes a submergible motor designed to drive a centrifugal pump that pumps the production fluid to the earth's surface. If the production fluid has a relatively high gas content, a gas separator is utilized as the pump intake. This allows gas to be separated from the fluid prior to entering the centrifugal pump.
Gas separators, such as those used in a downhole environment, often utilize a screw-type inducer mounted to a rotatable shaft. The screw-type inducer rotates within an outer housing, and uses centrifugal force to separate free gas. Specifically, the fluid mixture enters the outer housing through intake ports and moves to a lower section of the screw-type inducer. At this point, the pressure of the fluid is increased and moved through the transition section of the inducer into the centrifuge where the separation occurs. The fluid is forced to the outside of the separator and then through outlets to the centrifugal pump. Because the gas is lighter, it remains towards the center of the separator as the heavier liquid is forced to the outside. The lighter gas rises through the separator and is vented to the annulus between the submergible pumping components and the wellbore casing.
Because the entire screw-type inducer is rotated through fluid to increase the pressure on the fluid, substantial power is required. It would be advantageous to substantially reduce the mass of rotating components in the gas separator.